1. Field of the Invention
The present invention relates generally to a method and an apparatus for recognizing characters in a character recognizing apparatus, and more particularly to a method and an apparatus for recognizing characters in a character recognizing apparatus in which, when the character included in an input image is recognized, a misrecognized character can be efficiently removed.
2. Description of the Related Art
Character recognition is used when a document is scanned and converted into a text file or an electronic document. Recent developments in camera technology have caused a demand increase in character image processing by a camera in conjunction with mobile devices, such as Personal Data Assistants (PDAs) and cellular phones.
Contrary to the scanner to which a typical paper document is input, a camera performs character recognition by obtaining any type of character information. Character recognition using a camera recognizes any information such as a tourist location, various materials, a monument, a signboard, a business card and a menu. Character recognition using a camera can easily obtain and recognize characters by a portable camera, regardless of the medium in which the to-be-input characters are recorded, for which the research has been actively performed.
However, a disadvantage is that contrary to the scanner-based character recognition scheme, the condition under which the image is input is not limited so that the image recognized through the camera is significantly influenced by ambient light. Further, the camera-based character recognition scheme is not influenced by the environment. Thus, various types of characters are subjects for the recognition, and thus the rate of misrecognizing the character increases, making it difficult for the recognition apparatus to consistently perform.
According to a post-processing method in a conventional character recognition scheme, the character recognizing apparatus searches for a word including the characters recognized through the scanner in a database, such as a dictionary. If there is no corresponding word in the database, the apparatus determines the word as a misrecognized character. The character recognizing apparatus searches for the word most similar to the characters recognized through the scanner.
Generally, in recognizing characters using a camera, the background of the document is also photographed, as well as the document, and the photographed image includes both the document and the background. Therefore, the character recognizing apparatus or program receives the document image including the background, and cannot discriminate a document region from a background region. Thus, it even aims to recognize the characters in the background region. Particularly, the character recognizing apparatus misrecognizes the part having similar characteristics of the character in the background as the character, and includes the misrecognized character in the character recognition result. Accordingly, a broken character structure according to the recognition result occurs.
The foregoing camera-based character recognition scheme decreases the total rate of the character recognition, requiring the user to manually search for and delete each misrecognized result in the background. Such manual work for deleting the misrecognized character is inconvenient and unnecessarily time-consuming. As a further disadvantage, the manual work requires the user to directly select the document region in the photographed image. In addition, an apparatus for receiving the user input in the camera is limited to a button or touch screen. As many compact or automatic cameras do not even include a touch screen, users must bear the inconvenience of selecting the document region with a limited number of buttons. Furthermore, if the document region is in the form of a polygon and not a rectangle, the difficulty for the user to select only the document region is heightened.
Therefore, in order to improve the performance of the camera-based character recognition scheme, a need exists for a method and apparatus for recognizing a character having a post-processing function that can identify whether the character photographed by the camera is correctly recognized and amend the misrecognized character.